On 12. October 2007 a rock fall occurred from the Einser- Spitze (2.698m) in the Fischlein - valley (Dolomites), with an estimated volume of 60.000 cubic meters it was not an extraordinary large event, however the dust cloud resulting from the fragmentation of the dolostone was very impressive and reached even the village of Sexten.
Fig.1. Rock fall from the Einser-Spitze, photo from CARRARO 2008.
First minor rock fall occurred on the morning, the native Franz Tschurtschenthaler, noted a strange mist covering the mountain, and at closer examination with a binocular recognized minor rock falls under the hilltop. The weather was sunny at this day, and many hikers were on the way, Tschurtschenthaler warned them not to enter the valley for security reasons. As the largest rock fall occurred, covering the valley with a white cloud and dust, it was not clear if people were present in the area, so in a first moment alarm was given to the rescuers.
Fortunately the event resulted in a major scare, but without serious consequences. Also the raised dust, inhaled by some hikers and the rescue workers, resulted harmless.
The rock fall was probably triggered by the formation of ice in the faults characterising the lithology. Due the strong temperature variations in October between day and night, water melted and froze continuously, weakening the rock until the rock fall occurred.
CARRARO, C. (12.09.2008): Analyse und Monitoring der Felsstürze im Dolomiten-Raum: das Ereignis vom Einser - Sexten. Geologische Fachtagung der Autonomen Provinz Bozen - Südtirol